A clarification on Nano-T

I wish Nanotyrannus is its own genus or at least species... as fascinating as the idea of T-Rex having the monopoly over the giant predator niche in the latest Cretaceous of NA, it is always more interesting to have several of them... makes more sense, too, IMO, as long as they were adapted to hunt for different prey.

Alvin T. Grey wrote: »

It's a good bet their prey was different. If they are a different species (which in my opinion they are) then the teeth they had were the teeth they kept. One of the JH opinions is that the number of teeth, and the shape of teeth changed from juvenile T-Rex to adult, and hence Nano-T was a juvenile Rex. And the reason for the change in teeth was different prey items and hunting methods as the animal matured.

So if we agree with the premise that different dentation indicates different predation, then if Nano-T is a different species, it follows that Nano-T hunted different animals.

What is not being considered by Mr. H. is that many believe that Rex's hunted in packs. If that is true then they shared in the same kill.
We know that Allosaurs and Albertasaurs did. We think that daspletasaurs did, so it follows that Rex's may have.

If they shared the same kill, then they must have eaten the same kill.
If they ate that same animal, then their teeth need to be the same in order to do the job. Thank you Mr. darwin's finches.....

So if you agree with the above (based on sound principals that have been tested) Then what the Juvenile Rex theory seems to imply is that juvenile Rexs did not hunt with adults, or did not hunt the same prey.

In nature that is a wayyyyy too complicated solution.

Hmmm... I'm gonna have to disagree here. For starters, although Allosaurs and Albertosaurs have been found in groups, this doesn`t prove that they were hunting together. Komodo dragons are lone hunters, but they gather together to feed when there is a large carcass available. The young Komodos usually wait until the big ones finish their meal, but they still roam near waiting for their chance, so I can imagine a group of say, albertosaurs gathering together like this, attracted by the stench of a dead animal (or the smell of blood from a recent kill) and feasting together. You would find juveniles like in Komodo dragon gatherings without it meaning that they were part of a family group or "pack".

As for juvenile T-Rex not feeding on the same prey than adults, I don`t see why this should be strange. Adult crocodiles can feed on buffalo, zebra, you name it, but juveniles feed on fish and smaller animals simply because that's what they can capture. Same goes with sharks. I don`t think there is any hard evidence saying that juvenile T-Rex stayed with their parents and were raised and fed like (most) birds and mammals are today.
They could very well live separately (the juveniles probably forming small groups to protect themselves against predators, just like young crocodiles and some sharks do) and hunt small prey by themselves.
There's actually some evidence that certain herbivorous dinos such as Triceratops and some ornithomimids formed groups when they weren`t yet fully grown; kinda like teenager gangs, to protect themselves better against predators.
Since T-Rex is known to have been cannibalistic, it shouldn`t be surprising if young tyrannosaurs did the same. IMHO, anyways.

Alvin T. Grey wrote: »

Sorry Adam if this seems a little short, but it's busy as heck here at the moment. - I acknowldge the arguement, and understand it. But the flaw I see is in the tooth differences.
Dragons, Crocodiles etc do change their prey with time. Thats a function of the size of the animal I believe. Their dentition doesn't radically change though neither does their basic form or their method of hunting. Nano-Ts inner ear would have had to rotate about 10 degrees during this period in order to enable it to walk like a Rex without getting vertigo. It'd have to lose it's teeth and grow different types.
It would have to learn how to hunt one type of prey, then another when it grew up. Simply because it had different tools. And if we agree that the type of teeth an animal had was an indication of what it ate, then Nano-T didn't eat the same things as Rex.

Hmm ok I get it... may I ask what the differences between the teeth of T-Rex and Nano-T are? Because I only remember a difference in tooth number. I would expect a juvenile T-Rex to have more slender, blade-like teeth when compared to the adults, though.

Galvasean wrote: »

I know comparing human dentition to tyrannosaur dentition is akin to apples and oranges, but could tyrannosaurs have had a couple of layers of baby teeth which upon falling out gave way to the adult teeth? A human's baby teeth are very different to the adult set.
There have been dinosaurs found with varying tooth types in their mouths, so changing dentition is not a strictly mammalian trait...

If I remember correctly, baby crocodiles replace their teeth constantly and even faster than adults, like, once a month for each socket. If dinosaurs were anything like crocodiles (and they were in many ways), it wouldn´t make much sense to have a couple layers of baby teeth that will be replaced within a couple months anyways. I doubt the diet of the animal would change much during that time.
What we need is baby T-Rex fossils found ASAP!